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Robert Peirce Robert Peirce is offline
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Default Need advice for a small room

For me, stereo is about the imaging. I can't tell if my room is down
3db at 400hz, and frankly, I don't care as long as it sounds good. I
don't even go in for room treatment of any sort. Every room, including
a concert hall is going to have peaks and dips. I just live with that.

Right now I have a pair of Apogee Divas in a room that is about
15.5'x25'. Maybe I just got lucky, but I can walk just about anywhere
in the room and the image is locked in place. The only place this fails
is if I stand within a foot directly in front of one of the speakers.

I am planning to move and most of the rooms I am looking at tend to be
on the order of 10-12'. Sometimes they are almost square. I was all
hyped up on one product as a possibility for such a room until I found
out it was more about getting correct response from the room then the
kind of imaging I am after.

So, are there any imaging nuts out there who are dealing successfully
with small rooms? What are you doing?

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Peter Wieck Peter Wieck is offline
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Default Need advice for a small room

On Apr 26, 9:23=A0am, Robert Peirce wrote:
For me, stereo is about the imaging. =A0I can't tell if my room is down
3db at 400hz, and frankly, I don't care as long as it sounds good. I
don't even go in for room treatment of any sort. =A0Every room, including
a concert hall is going to have peaks and dips. =A0I just live with that.

Right now I have a pair of Apogee Divas in a room that is about
15.5'x25'. =A0Maybe I just got lucky, but I can walk just about anywhere
in the room and the image is locked in place. =A0The only place this fail=

s
is if I stand within a foot directly in front of one of the speakers.

I am planning to move and most of the rooms I am looking at tend to be
on the order of 10-12'. =A0Sometimes they are almost square. =A0I was all
hyped up on one product as a possibility for such a room until I found
out it was more about getting correct response from the room then the
kind of imaging I am after.

So, are there any imaging nuts out there who are dealing successfully
with small rooms? =A0What are you doing?


Yikes:

Coming in late, I get to see what has already been discussed to-date.
Cutting to the chase, I would refer you to advice published in the
early 1960s from no less than Acoustic Reseach on speaker placement.
Given that they specialized in acoustic-suspension 'bookshelf'
speakers of conventional/conservative (today) design, this will not
apply in detail to your speakers, but it will do so in general.

Take the longest wall in your room. Place one speaker (A) about two
woofer-diameters in from one corner. Place the other (B) about midway
between the first speaker and the other wall. Experiment with the
placement of speaker B until you have the what you perceive as the
best placement. Start with both speakers as close to the wall as
possible, moving only speaker B until you are happy. Then A out from
the wall (or not) and so forth. In/out from the wall affects bass
primarily. Distance from the walls and each other affects soundstage
primarily. Asymmetrical placement reduces/eliminates standing waves
and cancellation waves as well as multiple sorts of room effects.

This will give you the widest "sweet spot" available - closest to what
you (apparently) perceive in your present location.

Repeat the process on the shorter wall.

AR suggested at the time that if there was a listening audience and if
the listening room was used for other purposes than music, the long-
wall placement would quite regularly 'win' as it gave the greatest
audience spread. If for a single listener in a dedicated room, the
short-wall would win as the sweet spot could be made quite small. And
the natural progression to that concept is headphones.

OPINION (typical rant removed): I find the concept of a tiny sweet
spot as antithetical to the listening experience and about the
furthest thing from duplicating a live setting as is possible (except
for headphones). If I *must* keep my ears within a 12"/31cm cube in
order to realize the best possible performance from my speakers - that
is simply nuts.

Peter Wieck
Melrose Park, PA

AR3a
Maggie MG-III
Revox Piccolo
ARM5
AR14
AR Athena
Dynaco A25

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Audio Empire Audio Empire is offline
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Default Need advice for a small room

On Thu, 10 May 2012 06:10:57 -0700, Peter Wieck wrote
(in article ):

OPINION (typical rant removed): I find the concept of a tiny sweet
spot as antithetical to the listening experience and about the
furthest thing from duplicating a live setting as is possible (except
for headphones). If I *must* keep my ears within a 12"/31cm cube in
order to realize the best possible performance from my speakers - that
is simply nuts.

Peter Wieck
Melrose Park, PA

AR3a
Maggie MG-III
Revox Piccolo
ARM5
AR14
AR Athena
Dynaco A25


While I agree with you in theory, the reality is that the "sweet spot"
concept is part of the baggage that stereo recording methodology carries with
it. I've mentioned this before, but it doesn't hurt to reiterate:

When you are at a live, unamplified concert, and you move around with respect
the stage (or other locus of performance) your ears go with you and your
perspective changes with location. When listening to a recording, and you
move around the room, your surrogate ears, the microphones, and ultimately,
(in the case of multi-miked, multi-channel recordings) the final mix has one
set perspective because the "mikes" DON'T move. That being the case, there
is only ONE set place where the perspective is correct, IOW, there is only
one place in front of the speakers (right to left) where the listener is on
the same axis as the surrogate ears. Naturally, this is the place where the
imaging and soundstage snap into sharp focus. If you aren't in that spot, you
still hear a sound-field, but the focus will be gone. An analogy would be a
3-D visual image. As you move the right-eye image and the left-eye image
closer together and further apart, there is only one relative position where
these two images coalesce in your mind as a single 3-D image (assuming, of
course, you are wearing the glasses) with depth as well as height and width.
That's because your surrogate eyes are a pair of lenses on a camera that are
a set distance apart. That means that when viewing those images they must
give the illusion of being the same distance apart to your brain, or you
won't see the stereo effect - with or without the glasses.
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Gary Eickmeier Gary Eickmeier is offline
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Default Need advice for a small room

"Audio Empire" wrote in message
...

While I agree with you in theory, the reality is that the "sweet spot"
concept is part of the baggage that stereo recording methodology carries
with
it. I've mentioned this before, but it doesn't hurt to reiterate:

When you are at a live, unamplified concert, and you move around with
respect
the stage (or other locus of performance) your ears go with you and your
perspective changes with location. When listening to a recording, and you
move around the room, your surrogate ears, the microphones, and
ultimately,
(in the case of multi-miked, multi-channel recordings) the final mix has
one
set perspective because the "mikes" DON'T move. That being the case,
there
is only ONE set place where the perspective is correct, IOW, there is only
one place in front of the speakers (right to left) where the listener is
on
the same axis as the surrogate ears. Naturally, this is the place where
the
imaging and soundstage snap into sharp focus. If you aren't in that spot,
you
still hear a sound-field, but the focus will be gone. An analogy would be
a
3-D visual image. As you move the right-eye image and the left-eye image
closer together and further apart, there is only one relative position
where
these two images coalesce in your mind as a single 3-D image (assuming, of
course, you are wearing the glasses) with depth as well as height and
width.
That's because your surrogate eyes are a pair of lenses on a camera that
are
a set distance apart. That means that when viewing those images they must
give the illusion of being the same distance apart to your brain, or you
won't see the stereo effect - with or without the glasses.


No. Not analogous.

There need not be a single "sweet spot" nor a single perspective that was
viewed by some single stereo microphone.

The example in my Mars paper - which I think I sent you - was of an
imaginary recording made with one microphone per instrument, then played
back on speakers that have similar radiation patterns to the instrument they
are reproducing, and are placed in positions that are geometrically similar
to the original. Such an ideal system creates a sound field that is
spatially a duplicate of the original. You can move around in it just like
live. The realism of it depends on the size of the room being similar to the
original, or what the original would be good in. And most notably, neither
the recording nor the reproduction have anything to do with the number of
ears on your head or the spacing between them or any single position of any
microphone during the recording. Stereo is not a head-related system like
binaural, nothing to do with the human hearing mechanism, but rather the
creation of sound fields in rooms.

It is confusing when we begin to simplify the system down to fewer channels,
especially if it gets all the way down to two channels, because then we
begin to think that the two speakers are reproducing EAR SIGNALS, which they
are not. The only aspect of playback that relates to the human hearing
mechanism is the summing localization that is employed to create the phantom
imaging between speakers. Discrete surround sound with the center channel
gets us some of the way away from that confusion, but the nature of the
system remains the same, and the confusion will always be with us. But even
with a simplified-down system there needn't be a single sweet spot or single
perspective on the instruments, if you employ a proper radiation pattern,
speaker positioning, and a good room.

Gary Eickmeier


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Audio Empire Audio Empire is offline
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Default Need advice for a small room

On Fri, 11 May 2012 06:02:09 -0700, Gary Eickmeier wrote
(in article ):

"Audio Empire" wrote in message
...

While I agree with you in theory, the reality is that the "sweet
spot" concept is part of the baggage that stereo recording
methodology carries with it. I've mentioned this before, but it
doesn't hurt to reiterate:

When you are at a live, unamplified concert, and you move around
with respect the stage (or other locus of performance) your ears
go with you and your perspective changes with location. When
listening to a recording, and you move around the room, your
surrogate ears, the microphones, and ultimately, (in the case of
multi-miked, multi-channel recordings) the final mix has one set
perspective because the "mikes" DON'T move. That being the case,
there is only ONE set place where the perspective is correct, IOW,
there is only one place in front of the speakers (right to left)
where the listener is on the same axis as the surrogate ears.
Naturally, this is the place where the imaging and soundstage snap
into sharp focus. If you aren't in that spot, you still hear a
sound-field, but the focus will be gone. An analogy would be a 3-D
visual image. As you move the right-eye image and the left-eye
image closer together and further apart, there is only one relative
position where these two images coalesce in your mind as a single
3-D image (assuming, of course, you are wearing the glasses) with
depth as well as height and width. That's because your surrogate
eyes are a pair of lenses on a camera that are a set distance
apart. That means that when viewing those images they must give the
illusion of being the same distance apart to your brain, or you
won't see the stereo effect - with or without the glasses.


No. Not analogous.

There need not be a single "sweet spot" nor a single perspective
that was viewed by some single stereo microphone.

The example in my Mars paper - which I think I sent you - was of an
imaginary recording made with one microphone per instrument, then
played back on speakers that have similar radiation patterns to the
instrument they are reproducing, and are placed in positions that
are geometrically similar to the original. Such an ideal system
creates a sound field that is spatially a duplicate of the
original. You can move around in it just like live. The realism of
it depends on the size of the room being similar to the original,
or what the original would be good in. And most notably, neither
the recording nor the reproduction have anything to do with the
number of ears on your head or the spacing between them or any
single position of any microphone during the recording. Stereo is
not a head-related system like binaural, nothing to do with the
human hearing mechanism, but rather the creation of sound fields in
rooms.

It is confusing when we begin to simplify the system down to fewer
channels, especially if it gets all the way down to two channels,
because then we begin to think that the two speakers are
reproducing EAR SIGNALS, which they are not. The only aspect of
playback that relates to the human hearing mechanism is the summing
localization that is employed to create the phantom imaging between
speakers. Discrete surround sound with the center channel gets us
some of the way away from that confusion, but the nature of the
system remains the same, and the confusion will always be with us.
But even with a simplified-down system there needn't be a single
sweet spot or single perspective on the instruments, if you employ
a proper radiation pattern, speaker positioning, and a good room.


While much of what you say is true, with two channels, there is only a
very narrow range of listening positions where the aural images are in
focus. This has to be. Microphones aren't ears and they don't even ACT
like ears and in fact we don't want them to act like ears, because if
they did, we would have binaural recordings, not stereo recordings.
But they do build-up a snapshot of the performance from a fixed
perspective. It doesn't matter whether this perspective is the result
of some co-incident microphone technique such as M-S or ORTF, or
whether it's the result of widely-spaced omnis, or whether it's a
studio-mixed sound-field made up from the outputs of dozens of
microphones recorded to dozens of separate channels all mixed down to
two. The result, on the listener's end is the same. A fixed
perspective that does not move when the listener moves.

You are right again when you say that the only way around this is to
have a microphone and channel per instrument and a speaker on the
listening end per instrument all arranged exactly where the original
instrument was arranged during the recording process. This would give
the playback a similar image specificity to a real performance. Bell
Labs noted this in their 1933 stereophonic experiments. They started
with one channel per instrument (not recorded, of course, merely
piped-in by hard-wire from another, remote location) and kept reducing
the number of channels (on both ends) until but two remained. They
noted that it was entirely practical to convey the stereophonic
effect with merely two channels, but they also added the caveat that
with two channels, the optimum stereo effect was achieved only at the
point in front of the speakers where the sound-fields from the two
channels intersect.


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Gary Eickmeier Gary Eickmeier is offline
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Default Need advice for a small room

Audio Empire wrote:

While much of what you say is true, with two channels, there is only a
very narrow range of listening positions where the aural images are in
focus. This has to be. Microphones aren't ears and they don't even ACT
like ears and in fact we don't want them to act like ears, because if
they did, we would have binaural recordings, not stereo recordings.
But they do build-up a snapshot of the performance from a fixed
perspective. It doesn't matter whether this perspective is the result
of some co-incident microphone technique such as M-S or ORTF, or
whether it's the result of widely-spaced omnis, or whether it's a
studio-mixed sound-field made up from the outputs of dozens of
microphones recorded to dozens of separate channels all mixed down to
two. The result, on the listener's end is the same. A fixed
perspective that does not move when the listener moves.


Well, I hope you can see that this "fixed perspective" is a property of the
reproduction and not a basic property of the system. In fact, if you have a
multi-miked recording (which is NOT in incorrect technique in any sense)
then there IS no "perspective" from which the recording was made. If you had
the multitrack master, if it was recorded that way, then you could actually
pipe each mike thru a channel of its own out to a speaker positioned where
it was and you would have my example.

You are right again when you say that the only way around this is to
have a microphone and channel per instrument and a speaker on the
listening end per instrument all arranged exactly where the original
instrument was arranged during the recording process. This would give
the playback a similar image specificity to a real performance. Bell
Labs noted this in their 1933 stereophonic experiments. They started
with one channel per instrument (not recorded, of course, merely
piped-in by hard-wire from another, remote location) and kept reducing
the number of channels (on both ends) until but two remained. They
noted that it was entirely practical to convey the stereophonic
effect with merely two channels, but they also added the caveat that
with two channels, the optimum stereo effect was achieved only at the
point in front of the speakers where the sound-fields from the two
channels intersect.


Yes, again, playback only situation, not systemic. And I thought they ended
up with a three channel system.

The movie people are always one step ahead of the pure audio people. You can
see that at least with DD 5.1 surround sound, you can be anywhere in the
audience and perceive the center channel dialog as coming from the center of
the screen.

Stereo theory is constantly confused with binaural theory due to the
widespread use of the two channel system. We've got to shake that off and
start from scratch. I really like your example of the Innersound
electrostatics driving you mad. I had the same reaction to the Acoustats.
The classical theorists would think this an ideal situation, if the two
channels were "ear signals" meant to be piped to your ears. All that would
be missing would be crosstalk cancellation to get all the way to binaural
and total confusion.

I hope that your listening experience with the curved panel electrostatics
also includes a more natural, realistic sound field generated in your room.
Some listeners (Siegfried Linkwitz among others) realize that the reflected
sound can be a part of the realistic construction of the stereo image, and
in fact should be the same frequency response as the direct sound, not an
accidental byproduct of whatever sound comes off the back of a box speaker.

The whole theory of stereo is usually taken wrong because of these multiple
errors and misconceptions, and there doesn't seem to be a path out of it,
because of a lot of folklore and a lack of a single theory on exactly what
it is that we are doing with auditory perspective systems. Two channel
stereo is the main culprit, and multichannel is a partial solution, thanks
to the film people.

But can't we short-circuit all the cut and try fumbling and examine the
macro situation and state it once and for all?

Gary Eickmeier





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